Power-transmission gearing.



J I Aka [255151572 L.-B. GRAHAM POWER TRANSMISSION GEABING. APPLICATIONFILED JULY 23,1913.

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Patented Sept. 29, 1914.

2 SHEETS-SHEET l.

L. B; GRAHAM. POWER TRANSMISSION GEARING. APPLICATION FILED JULY 23,1913.

Patented Sept. 29, 1914.

2 SHEETS-SHBET 2.

the rotatable double Worm.

LESLIE B. GRAHAM, OF EAST CHICAGO,

INDIANA, ASSIGNOR (3F ()JflE-FL/LLF TU CLARENCE W'. TAYLOR, OF CHICAGO,ILLINGIS.

?OWELR-TBANSMISSIOI T GEABING.

Lil

Specification of Letters Patent.

Patented Slept. 29, 19145.

Application filed July 23, 1913. fieriol No. 780,675.

To (/U LIP/{02111 it "My come/1::

lie it known that, I, LasLin B. GRAHAM, a. citizen of the United Statesof America, residing at East Chicago, in the county. of Lake and Stateof .lndiana, have invented certain new and useful Improvements lll lo\.'er-'lransmission Mechanism, of which the following is a specification.

Mr invention relates to improvements 1n power transmission mechanism,and the objectsof my improvement are, first, to provide a constructionwhereby to afford a positive two-wheel drive under all conditions ineither direction, in motor vehicles; second, the provision of means toprevent the waste of power through'the vehicle wheel which o'l'l'er theleast resistance; third, to produce compensating mechanism that Wlllpermit either drive wheel to rotate faster than the other, in eitherdirection; fourth, to construct what is termed a double worm and Wormgear wheels in positive operative engage nicn't therewith operable onthe opposing ends of a divided shaft.

\lith the above and other objects in view, Ill) invention consists inthe novel features and in thonovel combination and arrangement of partshereinafter fully described, illustrated in the accompanying drawingsforming a part of this specification, and particularly pointed out inthe claims hereunto appended. I

Figure l is a longitudinal central'section of a rear aide of a motorvehicle with my invention applied thereto. Fig. 2 is a cross sei'itionalView on line 2-2 of Fig. 1' with parts shown in elevation. Fig. 3 isanelevation of what termed a double Worm with parts of itslc'ngtli'broken away to disclose the'teeth of two rotatable Worm gear wheels andtheir positions with reference to thedonble Wei-m. Fi nd is a detailview of an anti-friction; thrust bearing for each end of Fi 5 is a crosssectional View of a modified arrangement of the Worm gear Wheels withthe double Worm.

Similar numerals refer to similar parts throughout the several views. I

One embodiment of in present invention as applied to a motor ve iicle'is described as follows:

Referring to the drawings by reference numerals, 6 designates one partof a divided shaft with its squared end 7 on whichis saitably fixed aworm gear wheel 8 which. has a hub 9 with squared opening 10therethrongh. The teeth ll are suitably formed for en gagement in meshwith a double worm hereinafter more fully described. part 1210f thedivided shaft has a squared end 13 on. which is suitably tiz-red a wormgear wheel 14 with its huh 1.5 with squared opening 16 therethrongh. Theteeth 17 are suitably formed for engagement in mesh with the said doubleworm. The Worm wheel teeth 11 and l? have relatively opposite pitch.'

l8 denotes the left part and 119 the right part of two-piece rotatablehousing or member with left hub 20 and right hub 21. The two similarparts are secured together by bolts 22. The external annular flange hasfixed thereto bevel gear wheel 24. by rivets 25. On the inside ofeachsaid part 15 and 19 are formed recesses 26 and solid por tions 53? and28 therchetvveen.

31 is a double worm, loosely journaled on its own axis, positioned to bein mesh with both worm gear wheels, 8 and i l, to rotate in bearings 29and 30, and is carried by the rotatable housing. The double worm hasformed thereon left and right grooves or threads 32 and 38,respectively, and 15 provided withspindles 3e and rotatable in bearings29 and 39. The grooves or threads are formed at a suitable pitch tooperative-1y lI'ltQI'lQn'lC with the teeth of the two worm gear"-a'heels to move them in the direction of rotation and to permitrelative rotative movement of the wheels.

In Fig. 4- an annularseries of anthfric tion balls or rollers arepositioned between plates 37 and 38110 malts sensitive and responsivethe double Worm when compensating; action of the worm is necessary.

In Fig. 5 is indicated a mot "fled arrangenient of worm gear wheels inrespect to the double worm. On thing this change of po',

'sition adords is a more compact construction.

Tl e anti-friction element is disposed at each end of the Worm.

39 is a non-rotatable housing, and 40 13 a pinion on the engine shaft(not shown) in" mesh with the usual bevel gear Wheel which is fixed tothe rotatable housing made up of parts l8 and 19.

'l'he other mesh with both worm Vv hen power is applied to the rotatablehousing, the right and left thread or threads if the worm being in meshwith the teeth of both of the worm gear wheels, thahousing movcs'theworm bodily and rot-ates both worm gear wheels in either direction atthe same rates of speed until the speed of one worm gear wheel isgreater hen the other when. it is free to relatively rotate faster thanthe other worm gear wheel. In a straight forward movement of the vehiclethe right and left threads of the worm in gear wheels oppose each otherstendency to rotate the worm on its own axis until the speed of onevehicle wheel is relatively greater, when the over-running or runningahead of one wheel permits the worm or worms to rotate and the housingto run ahead of the slower wheel and the faster wheel to move ahead ofthe housing. The relatively greater speed of one "vehicle wheel iscaused by the road power or the traction of such vehicle Wheel while incontact with the road surface, as, for example, when turning a corner orswerving from a straight ahead course. This action of the double worm orworms can only occur when there is difference in the speed of the twovehicle wheels.

Because of the -worm having'reversely extending or right and left handthreads cut in its surface, the action of the teeth of each worm wheel,when no power is applied by the motor the faster worm wheel by reasonoi? its teeth being in mesh with the double worm will cause the worm torotate in the same direction that the faster wheel has tendency torotate it.

I In double chain drive, the compensating mechanism is mounted on theopposing ends of the jack shaft instead of the rear axle.

Changes, variations and modifications in the details and arrangement ofmy invention within the scope of the claims, may be resorted to withoutdeparting from the spirit or sacrificing any of the advantages thereof.Therefore, I do not limit my in rcntion to the exactconstruction and ar-'rangement of the shown and described.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. In power transmission mechanism of the differential type, incombination, one or more double worms, Worm wheels fixed to independentshafts, said worms each being in mesh with both of said worin wheels,and a rotatable housing carrying said double worms in a manner forbodily rotation thereof, each Worm being loosely journaled on its ownaxis 2..In power transmission mechanism, in

combination, independent shafts, a worm wheel fine. to one end of eachshaft, one or more d worms being in mesh with both of said. worm wheels,a rotatable housing carrying the double worm or worms suitably bodilyrotation thereof, each worm being loosely journalcd on its own axis, andmeans to rotate said housing.

3. In power transmission mechanism, in combination. one or more wormseach having right and le'tt threads formed circumfercniially thereon andtwo worm wheels fixed to separate shat s, said worm-wheels being suitabiy it n med for intcrme hin rcngagcu'ient with each oi said worms,and to permit relative rotatiie movement of said worm Wheels, arotatable housing suitably formed to carry each of said worms for bodilyrotation there with, each worm being loosely journals-d on its own axis,and mea to rotate said housing.

'4. In power transmission mechanism, in combination, a rotatable housingformed with worm-recesses and anti-friction wormend bearinqs, one ormore worms each having right and left threads formed thorcon and carriedby said rotatable housing, each said worm being loosely journaled on itsown axis, a divided shaft, a worm wheel fixed to one end of eachshafteach said worm being in mesh with both 0% said worm wheels, and means torotate said housing.

5, In power. transmission mechanism, in combination, independent shafts,a worm wheel fixed 'to one end of each shaft, :1 r0- tatable housing"Formed with worm-recesses, one or more worms each having right and leftthreads formed thereon and rotatably carried by said rotatable housineach said worm being in mesh with both 0. said worm wheels and rotatablebodily, and means to rotate said housing.

6. In power transmission mechanism, in combination, independent shafts,a worm wheel fixed to one end of each shaft one or more worms eachhaving right and left threads formed circumfcrentially thereon, eachsaid worm being in mesh with both of said worm wheels, arotatablehousing formed with worm-recesses and anti-friction worm-end o arings,each said worm being suitably carried by said housing for bodilyrotation, each. said worm loosely journaled on its own 315;, and meansto rotate the housing.

In testimony whereof I atfix my signature in presence of two witnesses.

LESLIE B. GRAHAM.

' Witnesses:

' C. Ri mann Bs'rTs,

Scorr .Lvl. HOGAN.

